Radu Matei

Added logging in f3c403fe4dbf74b64aedf5ec7c2a042c63131648

The `Context` struct seems to be a good place for the Logger

Also add example with Application Insights Go SDK for logging

`ctx.Logger.Log` should be `ctx.Logger.Logf`

Added CircleCI integration - https://circleci.com/gh/radu-matei/azure-functions-golang-worker

Setup Docker image build as part of CI

Currently there are no tests whatsoever - there need to be at least the structure in place to further add tests.

Added blob binding - in - see https://github.com/radu-matei/azure-functions-golang-worker/blob/master/sample/HttpTriggerBlobBindingGo/main.go#L9

Added initial support for blob binding - out - see https://github.com/radu-matei/azure-functions-golang-worker/blob/master/sample/HttpTriggerBlobBindingInOutGo/main.go

Starting with https://github.com/radu-matei/azure-functions-golang-worker/commit/53fd54d4aebbfda4f15f9494f7608636ae7e33a9 you can now return any type from the user function. The way Azure Functions return works, any out bindings (like writing to a blob, for example) have...